Spinal fixation systems such as pedicle screw and rod constructs are commonly used to promote fusion between intervertebral bodies. The insertion of pedicle screws typically requires a linear “line-of-approach” trajectory that is aligned with the longitudinal axis of the screw, in order to accommodate the access and delivery instruments. Similarly, anchors such as bone screws may be used to directly fix intervertebral implants to vertebral bodies, typically requiring the insertion of several screws at unique angles oblique to the sagittal and/or transverse plane, and thus multiple lines-of-approach. However, in a variety of surgical situations, achieving a desired trajectory for screw insertion can be difficult due to the patient's anatomy obstructing a linear line-of-approach. For example, medially-directed placement of pedicle screws into the sacrum is desirable to prevent screw loosening and/or pullout, but can be prohibited due to the iliac crest obstructing the linear line-of-approach.